[PATCH] D137632: [LoopPredication] Widen checks if condition operands constant ranges are known

[Yevgeny Rouban via Phabricator via llvm-commits]

yrouban added inline comments.


================
Comment at: llvm/lib/Transforms/Scalar/LoopPredication.cpp:840
+
+  if (RHSRange.isFullSet()) {
+    LLVM_DEBUG(dbgs() << "RHS range is full-set\n");
----------------
do it right after RHSRange = ComputeRange() and only then calculate LHSRange.


================
Comment at: llvm/lib/Transforms/Scalar/LoopPredication.cpp:852
+  if (IsSigned)
+    LHSMaxIsGreaterThanRHSMax = LHSMaxValue.sgt(RHSMaxValue);
+  if (LHSMaxIsGreaterThanRHSMax) {
----------------
mkazantsev wrote:
> ```
>   if (IsSigned)
>     LHSMaxIsGreaterThanRHSMax = LHSMaxValue.sgt(RHSMaxValue);
>   else
>     HSMaxIsGreaterThanRHSMax = LHSMaxValue.ugt(RHSMaxValue);
> ```
> ?
or
```
bool LHSMaxIsGreaterThanRHSMax = IsSigned
                               ? LHSMaxValue.sgt(RHSMaxValue)
                               : LHSMaxValue.ugt(RHSMaxValue);
```

or even a bigger change without introduced LHSMaxValue and RHSMaxValue:
```
bool IsGreaterThanRHSMax = IsSigned
                         ? LHSRange.getSignedMax().sgt(RHSRange.getSignedMax())
                         : LHSRange.getUnsignedMax().ugt(RHSRange.getUnsignedMax());
```



CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137632/new/

https://reviews.llvm.org/D137632